Characterization and optimization of a dual channel PERCA for the investigation of the chemistry of peroxy radicals in the upper troposphere [Elektronische Ressource] / von Deniz Kartal

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2009
• Nombre de lectures: 17
• Langue: English
• Poids de l'ouvrage: 26 Mo

Extrait

Characterization and optimization of a dual channel PERCA for the
investigation of the chemistry of peroxy radicals in the upper troposphere







Deniz Kartal









Universität Bremen 2009
Characterization and optimization of a dual channel PERCA for the
investigation of the chemistry of peroxy radicals in the upper troposphere


Vom Fachbereich für Physik und Elektrotechnik
der Universität Bremen



zur Erlangung des akademischen Grades eines
Doktor der Naturwissenschaften (Dr. rer. nat.)
genehmigte Dissertation


von
M.Sc. Deniz Kartal
wohnhaft in Bremen




1. Gutachter: Prof. Dr. J.P. Burrows
2. Gutachter: Prof. Dr. Peter Lemke

Eingereicht am: 01.09.2009
Tag des Promotionskolloquiums: 09.10.2009

INDEX
ABSTRACT
INTRODUCTION
1 THEORETICAL BACKGROUND ....................................................- 1 -
1.1 Main physical features of the atmosphere ..................................................................................... - 1 -
1.1.1 Vertical variation of atmospheric pressure and temperature........................................................... - 1 -
1.1.2 Large Scale Motion of the atmosphere.......................................................................................... - 6 -
1.1.2.1 The General Circulation....................................................................................................... - 6 -
1.1.2.2 Troposphere-Stratosphere Exchange .................................................................................... - 7 -
1.1.2.3 Mesoscale convective systems ............................................................................................. - 8 -
1.1.3 Radiation and molecule interaction in the atmosphere ................................................................. - 10 -
1.2 Radicals in the Troposphere ........................................................................................................ - 11 -
1.2.1 Sources of peroxy radicals ......................................................................................................... - 12 -
1.2.2 Sinks of Peroxy radicals ............................................................................................................. - 17 -
1.3 Basics of Chemical Kinetics ...... - 19 -
1.4 Measurement techniques of Peroxy radicals ............................................................................... - 23 -
1.4.1 Laser Induced Fluorescence (LIF) .............................................................................................. - 23 -
1.4.2 Matrix Isolation-Electron Spin Resonance (MIESR) ................................................................... - 23 -
1.4.3 Chemical Ionisation Mass Spectroscopy (CIMS) ........................................................................ - 24 -
1.4.4 Peroxy Radical Chemical Amplification (PERCA) ..................................................................... - 25 -
1.4.4.1 Principle of the measurement technique ............................................................................. - 25 -
1.4.4.2 General factors influencing the CL..................................................................................... - 28 -
2 OBJECTIVES ...................................................................................... - 31 -
3 EXPERIMENTAL ............................................................................... - 33 -
3.1 Dual Channel PERCA: DUALER ............................................................................................... - 33 -
3.1.1 Main components of the DUALER............................................................................................. - 33 -
3.1.2 Operation conditions of the DUALER ........................................................................................ - 38 -
3.2 Experiments under pressure controlled conditions ..................................................................... - 40 -
3.2.1 Pressure Chamber ...................................................................................................................... - 40 -
3.2.2 Installation of DUALER to Pressure Chamber ............................................................................ - 43 -
3.3 Calibration Procedures ................................................................................................................ - 45 -
3.3.1 NO Calibrations ........................................................................................................................ - 45 - 2
3.3.2 Chain Length Determination: HO c alib ra tio n ............................................................................. - 46 - 2
3.3.2.1 Determination of effective absorption cross section of oxygen ............................................ - 47 -
3.3.2.2 Determination of the ozone production of the radical source ............................................... - 49 -
3.4 Error Analysis ............................................................................................................................. - 50 -
3.5 Installation and operation of DUALER at DLR-Falcon ............................................................. - 53 -
4 MODELLING STUDIES..................................................................... - 57 -
4.1 Fourth order Runge-Kutta method ............................................................................................. - 57 -
4.2 Description of the chemical box model ........................................................................................ - 59 -
5 MEASUREMENT CAMPAIGN AMMA SOP2................................. - 65 -
5.1 Overview of the IUP-UB contribution to the AMMA project ..................................................... - 69 -
6 RESULTS AND DISCUSSION ........................................................... - 71 -
6.1 Laboratory Characterization and Optimization of the DUALER .............................................. - 72 -
6.1.1 Pressure dependency of the NO detector sensitivity ................................................................... - 72 - 2
6.1.2 Pressure dependency of the chain length ..................................................................................... - 74 -
6.1.3 Characterization of the effect of pressure variations for the DUALER ......................................... - 79 -
6.1.3.1 Pressure dependency of NO detector sensitivity of DUALER ............................................ - 80 - 2
6.1.3.2 The characterization of CL of DUALER reactors ............................................................... - 82 -
6.1.4 Characterization of the of the DUALER pre-reactor nozzle ......................................................... - 85 -
6.1.5 Determination of eCL with CH O and HO mixture .................................................................. - 93 - 3 2 2
6.1.6 Application of laboratory experiment results .............................................................................. - 96 -
6.2 Analysis of airborne measurements during AMMA 2006 ........................................................... - 97 -
6.2.1 Determination of effective calibration parameters for monitoring detector sensitivities ................ - 98 -
6.2.2 Effect of relative humidity in the DUALER measurements during AMMA ............................... - 104 -
*
6.2.3 Error analysis of the airborne RO measurements .................................................................... - 109 - 2
6.2.4 Analysis of peroxy radical measurements during AMMA ....................................................... - 114 -
*6.2.4.1 RO measurements within convective episodes ................................................................- 115 - 2
*6.2.4.2 RO measurements in biomass burning plumes 122 - 2
*6.2.4.3 Vertical distribution of RO over Ouagadougou ...............................................................- 129 - 2
7 SUMMARY AND CONCLUSIONS ................................................. - 133 -
APPENDIX 1 ............................................................ - 137 -
APPENDIX 2 ................................ - 141 -
REFERENCES ......................................................... - 145 -
ACKNOWLEDGEMENTS ..................................................................... - 153 -
CURRICULUM VITAE .......... - 155 -


ABSTRACT
The research of peroxy radical chemistry is an important topic that provides essential
knowledge about photo oxidant formation and night time chemistry. Peroxy radicals play an
important role in the formation and depletion reactions of ozone in the troposphere. They also
play a key role in the cleaning processes of the atmospheric pollution.
At the Institute of Environmental Physics (IUP) of the University of Bremen,
laboratory studies are performed to characterize and design a dual channel reactor system
(DUALER: DUal channel Airborne peroxy radical chemicaL amplifiER) for the
measurements of peroxy radicals on an airborne platform in the upper troposphere. The IUP
DUALER system, based on the PERCA (Peroxy Radical Chemical Amplification) technique
was deployed on the DLR-Falcon 20 of German Aerospace Centre (DLR)